International Agency for Research on Cancer (IARC) - Summaries & Evaluations


VOL.: 40 (1986) (p. 317)

CAS No.: 20073-24-9
Chem. Abstr. Name: 7-Oxo-7H-furo[3,2-g][1]benzopyran-6-carboxylic acid, ethyl ester

5. Summary of Data Reported and Evaluation

5.1 Exposure

There is no known human exposure to 3-carbethoxypsoralen, other than in limited clinical trials for the treatment of psoriasis.

5.2 Experimental data

3-Carbethoxypsoralen was tested for skin carcinogenicity in two experiments in two strains of mice by skin application with and without ultraviolet A radiation and in one study in mice by intraperitoneal administration with subsequent ultraviolet A radiation. No skin tumour was observed in 3-carbethoxypsoralen-treated mice in any of the three studies, with ultraviolet A radiation. The studies were inadequate to evaluate the systemic carcinogenicity of 3-carbethoxypsoralen.

No data were available to evaluate the reproductive effects or prenatal toxicity of 3-carbethoxypsqpen to experimental animals.

In the presence of ultraviolet A radiation, 3-carbethoxypsoralen bound covalently to isolated DNA and induced DNA damage in Salmonella typhimurium, Escherichia coli and Saccharomyces cerevisiae. It was not mutagenic to Salmonella typhimurium in the dark in the absence of an exogenous metabolic system. In combination with ultraviolet A radiation, 3-carbethoxypsoralen induced mutations and mitotic recombination in yeast and mutations and sister chromatid exchanges in cultured mammalian cells in vitro.

5.3 Human data

No case report or epidemiological study of the carcinogenicity of 3-carbethoxypsoralen was available to the Working Group.

5.4 Evaluation

On the basis of experiments designed to test only the carcinogenicity to mouse skin of 3-carbethoxypsoralen in combination with ultraviolet A radiation, there is no evidence of carcinogenicity to experimental animals.

There is inadequate evidence for the carcinogenicity to experimental animals of 3-carbethoxypsoralen in the absence of ultraviolet A radiation.

No evaluation could be made of the carcinogenicity of 3-carbethoxypsoralen to humans.

For definition of the italicized terms, see Preamble Evaluation.

Subsequent evaluation: Suppl. 7 (1987) (p. 59: Group 3)


Last updated: 22 April 1998

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